So, as it turns out, a violent sibling can become much worse than previously thought. But more importantly, they can also become much better people through learning the right lessons and undergoing the right experiences. Lynn Jr has always been a rough and violent type of person, and to an extent, that will always be in her nature. It's just the type of person she is. But provided she doesn't take that nature of hers too far and remains a caring and supportive individual towards her friends and family, it's fine. That is the person she has become. Through experiencing a great downfall, the sporty Loud girl was able to pull herself up and emerge from the conflict with her brother as a much better person. Now both she and Lincoln are better off because of what happened between them.
Lincoln has grown to enjoy the (relatively) calm and peaceful atmosphere which has existed within the walls of the Loud House recently. One of his most destructive and antagonistic sisters has been far more assertive and reasonable towards him since the events of their little football game, rather than aggressive and vile. He still succumbs to the occasional prank or instance of rough treatment every once in a while, but his jock sister never takes it too far anymore. Her treatment now comes across as legitimate rough love rather than abuse. Lincoln also enjoys some respect from his peers at school, which he gained from scoring the winning points for his team during the game. Also, Rusty and the others know that if they turn on him and start excluding him from the group or pick on him, then they will have to answer to his tough as nails sister.
Speaking of which, Lynn's role as Lincoln's tough big sister came back to benefit him in the end. Some time after their relationship was reformed, Lincoln ran into another problem. He had another bully come along and antagonise him at school. Let's just say, once Lincoln's jock sister found out, that bully was taught a HARD lesson, and never dared touch Lincoln again. It was very refreshing for Lincoln to experience the positive side to having a tough sibling in the family, for a change. It was made clear that despite the years of rough treatment, Lynn was a sister who would stand by his side and help him out when he needed it.
Lynn continues to play every sport known to man and play for multiple sports teams throughout Royal Woods, except no longer as the leader of any of them. Those roles have been delegated to other players. Of course, given her immense talent, she is looking to quickly rise back up the ranks, and then, when ready to do so, possibly reclaim some of those leadership roles. She has learned to be more respectful and appreciative of her fellow jocks. Margo and the other girls have all enjoyed Lynn's new assertive attitude almost as much as Lincoln himself.
Eventually, a new girls football league was formed in the area, and Lynn began to play alongside her friends, now being part of two teams (since she still plays for the Royal Woods Roosters in the boys league). Her, Margo, Polly and the others all became prestigious members of the team and helped bring great success to it. Ronnie Anne also ended up joining the team, and she fit right in with Lynn and the other rough girls, given her own tough and tomboyish personality. While not competing on opposite teams, the two of them turned out to make great friends.
Indeed, Lincoln may constantly have problems in his family, and come into conflict with his sisters many times, but at the end of the day, they are family, and they will always be there for each other. Lincoln and Lynn have had one of the most troubling relationships in the household, but it's clear there is still a strong sibling bond in place behind all the roughness. As Lincoln once came to realise himself, despite being the only boy in the group of siblings, Lynn is practically an honorary brother... and he wouldn't have it any other way.